In camera devices with multiple optical chains, e.g., camera modules, images are captured by individual camera modules. The images are then sometimes used to generate a composite image.
In the case of camera modules which use rolling shutters, different portions of an image are exposed, e.g., captured, and then read out at different times. Over time objects in a scene area may move, particularly in the case where an image includes individuals or objects which may be in motion. Since camera modules which use sensors with rolling shutters capture different portions of a scene at different times, within a single image this may cause some distortions, e.g., a streak, in the direction of motion and/or other image distortions.
In camera devices with multiple optical chains, image capture is often controlled so that each of the sensors captures and reads out lines of an image, e.g., rows of pixel values, from one edge of a sensor to another with all the sensors of the camera device proceeding in the same direction, e.g., from top to bottom, in terms of reading out of rows of pixel values as part of a rolling shutter operation.
This approach can work well for some systems where the optical chains and/or corresponding sensors are arranged in a uniform array. However, in the case of non-uniform camera module arrangements where some sensors may be oriented differently from other sensors, this can result in different areas of a scene being captured at different time periods with, for example, some camera modules capturing the top of a scene area while other camera modules are capturing the bottom of the scene area due to the different orientations of the camera modules. Such different orientations are particularly possible in the case where mirrors are used in camera modules and the camera modules have various orientations within a camera device in order to facilitate including multiple camera modules in the limited space available in a camera device.
In view of the above discussion it should be appreciated that there is a need for methods and apparatus which allow images captured by different camera modules, e.g., optical chains, to be captured in a manner that takes into consideration the orientation and/or configuration of a camera module. In the case of camera devices with one or more sensors which use a rolling shutter, it would be desirable if the orientation of the camera module and/or sensor in a camera module could be taken into consideration when controlling the readout of lines of pixel values to reduce or avoid differences between the time different modules capture the same portion of a scene as compared to the case where all camera modules capture images using the same direction of sensor read out.